The dollar-real pair "tested $2.10 last week, the proverbial line in the sand of what was perceived as a de facto band of $2.00-2.10," he wrote in a note to clients. "Now many market participants are calling for a $2.30 target," he adds, suggesting they would be comfortable with an even weaker real.

But lo and behold, the central bank recently intervened when the real hit $2.10. "Does the intervention confirm that the 2.00-2.10 paradigm is intact?" Solot asks rhetorically. Perhaps, he says, they were just trying to "slow down the move and avoid panic selling." Or maybe, he says, "the action was a proxy for more confrontation between the central bank and the finance ministry as both institutions struggle for credibility while juggling far too many macroeconomic targets for their own good."

Either way, Solot says, the direction of the real is unclear.

"We stick to our view that the range will hold for the time being and that for the short term, a move lower in USD/BRL is more likely than a decisive break of the $2.10 level," he says. Even so, "low implied yields below 6% and now more policy uncertainty do not argue for taking new large BRL bets - at least not until we get more clarity."